What is Convection?

Convection is the process by which heat is transferred through the movement of fluids, including liquids and gases. This transfer occurs when warmer, less dense areas of a fluid rise, and cooler, denser areas sink, creating a circulation pattern that effectively distributes heat. This is a key concept in energy efficiency and building performance, as understanding convection can help in designing systems that manage temperature and airflow effectively within a building.

The other choices describe different forms of heat transfer. The transfer of heat through solids refers to conduction, while the flow of heat through stationary molecules indicates a lack of movement and does not accurately depict convection. Heat transfer in a vacuum involves radiation, a different method where heat is transferred without a medium, as there are no molecules present to conduct or convect heat. Therefore, the option that correctly defines convection is the one that highlights its application in fluids.